1 /*
2 * Copyright (C) 2013-2021 Canonical, Ltd.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 *
18 * This code is a complete clean re-write of the stress tool by
19 * Colin Ian King <colin.king@canonical.com> and attempts to be
20 * backwardly compatible with the stress tool by Amos Waterland
21 * <apw@rossby.metr.ou.edu> but has more stress tests and more
22 * functionality.
23 *
24 */
25 #include "stress-ng.h"
26
27 /*
28 * stress_mlock_region
29 * mlock a region of memory so it can't be swapped out
30 * - used to lock sighandlers for faster response
31 */
stress_mlock_region(const void * addr_start,const void * addr_end)32 int stress_mlock_region(const void *addr_start, const void *addr_end)
33 {
34 #if defined(HAVE_MLOCK)
35 const size_t page_size = stress_get_pagesize();
36 const void *m_addr_start =
37 (void *)((uintptr_t)addr_start & ~(page_size - 1));
38 const void *m_addr_end =
39 (void *)(((uintptr_t)addr_end + page_size - 1) &
40 ~(page_size - 1));
41 const size_t len = (uintptr_t)m_addr_end - (uintptr_t)m_addr_start;
42
43 return shim_mlock((const void *)m_addr_start, len);
44 #else
45 (void)addr_start;
46 (void)addr_end;
47
48 return 0;
49 #endif
50 }
51